反应详情

To a solution of 6-bromo-2-phenylchroman-4-one (387 mg, 1.28 mmol) in anhydrous DCM (10 mL) was added TiCl4 (1 M solution in DCM, 2.6 mL, 2.6 mmol) dropwise within 15 minutes at room temperature. The resulting mixture was stirred for 1 h after the addition. To this mixture was added bis-trimethylsilylcarbodiimide (525 mg, 2.82 mmol) dropwise. The resulting mixture was stirred for 18 h after the addition. The reaction mixture was poured into ice-water (50 g) and extracted with DCM (3×30 mL). The combined organic phases were dried over anhydrous Na2SO4, filtered, and concentrated to give (Z)—N-(6-bromo-2-phenylchroman-4-ylidene)cyanamide (400 mg, 96%) which was used in next step without further purification.

1. additionafter the addition
2. stirringThe resulting mixture was stirred for 18 h
3. additionafter the addition
4. extractionextracted with DCM (3×30 mL)
5. dry with materialThe combined organic phases were dried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationconcentrated